This book has been inspired by existing documentation, and among them, some very good blogs and websites. We also highly recommand you get in contact with members of the OpenStreetMap community, to get some support, inspiration, solutions and ideas.

http://egsc.usgs.gov/isb/pubs/gis_poster/ is a poster provided by the United States Geological Survey that is useful for the background and history of Geographic Information Systems and examples of GIS technology in use.

IRC channel for OpenStreetMap is #osm on oftc.net. There are other IRC channels available for different languages and topics. You can see a list of all different IRC channels in http://wiki.openstreetmap.org/wiki/IRC.